The present invention relates to a method whereby colors derived from iron complexes and which are to be employed in dry foods or in dry mixes for liquid systems are stabilized without loss of color hue in the dry color powder or in the product units which the stabilized iron color complex is incorporated. More specifically, the immediate invention concerns co-drying either the ferric ion component of the color complex or the entire complex on an edible inert diluent to obtain such a result.
It is known that ferric salts form complexes with certain phenols to produce deep colors as those employed in ink. Recently it has been discovered that certain .alpha.-hydroxy carboxylic acids as well as certain of their ethers and esters and 3 or 5-hydroxy-4-pyrone-structured compounds such as 3 hydroxy-2-methyl-4-pyrone, known commercially as "Maltol," complex with ferric ions to form yellow and red to burgundy colors respectively. These colors are the inventive disclosures of two patent applications being filed concurrently with the immediate invention herein incorporated by reference. Both applications are entitled "New Color Composition." The application relating to red color complexes is authored by Dr. Richard Scarpellino, General Foods Corporation, Ser. No. 607,409. The application relating to yellow color complexes is by Dr. Thomas H. Parliment, General Foods Corporation, now U.S. Pat. No. 3,974,197.
It has been found that iron complex colors such as those formed by iron-phenol complexes, iron-maltol complexes and iron .alpha.-hydroxy carboxylic acid complexes are very hygroscopic due it is thought to the presence of the ferric ion. When employed in dry food systems, these complexes tend to form small sticky spots on the surface of the dry mix on storage with some color loss if the reaction is allowed to run rampant. In addition, oftentimes the food system in which these colors are to be employed must be reformulated to delete ingredients which would preferentially complex with the ferric ion resulting in appreciable if not total color loss. This invention provides a method of stabilizing iron complex colors whereby formation of these spots and consequent color loss is prevented and reformulation of the food system is in some instances not necessary, making these color complexes more suitable for use in virtually any dry food or beverage mixes which are normally packaged and stored for extended periods of time.